Various methods have been developed for payment of carrier services. These payment methods include postage stamps which are individually applied to each mailpiece and metered imprints which are also individually applied to each mailpiece. Additionally, other systems have been developed such as permit mail where a carrier issues a permit allowing certain types of mailing and manifest systems wherein mail is manifested and delivered to a carrier service along with the manifest.
In a mail production environment, where large batches of mail are produced, each of the above payment methods involves compromises between ease of use and security for the payment of postage to the carrier service. Stamped mail requires costly printing of stamps by the carrier service, as well as costly control and revenue accounting for the stamps. Moreover, the utilization of stamps as a payment method provides little information to the carrier service related to the cost associated with operating any particular facility or any particular class of mail delivery service provided. Additionally, the utilization of stamps particularly in a large mail production environment, does not easily accommodate multiple rate mailings. Mechanical dispensing of stamps is slow and prone to malfunction. The labor and time involved in purchasing of stamps by the mailer is costly, and security is limited due to theft, of stamps and reused or "washing" of stamps.
Traditional metered mail provides a significant level of security for the carrier service. However, in high volume production mail environment variable weight mailings may require multiple meters to achieve high throughput speeds and mechanical malfunctions may frequently occur for high volumes of mail printed by meters with mechanical printing mechanisms.
Many of these problems have been alleviated with the advent of new electronic postage meters, particularly postage meters which are adapted to print with digital printing technologies. Enhanced security has been obtained with postage meters with digital printing through the use of encrypted indicias. The encrypted indicias employ a digital token which is encrypted data that authenticates the value and other information imprinted on the mailpiece. Examples of systems for generating and using digital tokens are described in U.S. Pat. No. 4,757,537 for SYSTEM FOR DETECTING UNACCOUNTED FOR PRINTING IN A VALUE PRINTING SYSTEM; U.S. Pat. No. 4,831,555 for UNSECURED POSTAGE APPLYING SYSTEM; and, U.S. Pat. No. 4,775,246 for SYSTEM FOR DETECTING UNACCOUNTED FOR PRINTING IN A VALUE PRINTING SYSTEM. Because the digital token incorporates encrypted data including postage value, altering of the printed postage revenue and the postage revenue block is detectable by an appropriate verification procedure. Moreover, systems have been proposed for postal payment with verifiable integrity to detect attempts to interfere with the rating process for the postage amount to be imprinted as opposed to interference with the resulting printed postage value. In this connection, reference is made to U.S. Pat. No. 5,448,641 for POSTAL RATING SYSTEM WITH A VERIFIABLE INTEGRITY.
Both permit mail and manifest mail systems, as well as related contract mail systems, usually have no evidence of postage payment on individual mailpieces and require complex and extensive acceptance procedures and associated documentation. These systems are very complex, time consuming and inaccurate for the carrier service in administering and accepting mail. Moreover, the funds security of the system is vulnerable since it is open to undetectable collusion. Once permit mail has been accepted into the carrier mail delivery system, it is extremely difficult to determine whether the mail has been paid for. Furthermore, because of the various techniques used for payment adjustments, a significant loss of revenue or over payment by either the carrier or the mailer, as the case may be, is possible since payment is verified only by a sampling method. In addition, systems of this type are very complex for the mailer, are error prone and require extensive documentation. Further, the risk of overpayment by the mailer or the requirement to redo the documentation and mail due to adjustments exists in these systems. Additionally, the systems of this type involve time consuming costly acceptance procedures. Moreover, for certain of these permit payment systems, preprinted envelopes must be maintained in inventory.
An improved manifest system has been proposed, for example, as set forth in U.S. Pat. No. 4,907,161 for BATCH MAILING SYSTEM, U.S. Pat. No. 4,837,701 for MAIL PROCESSING SYSTEM WITH MULTIPLE WORK STATIONS; U.S. Pat. No. 4,853,864 for MAILING SYSTEM HAVING POSTAL FUNDS MANAGEMENT; U.S. Pat. No. 4,780,828 for MAILING SYSTEM WITH RANDOM SAMPLING OF POSTAGE; and U.S. Pat. No. 5,675,650 for CONTROLLED ACCEPTANCE MAIL PAYMENT AND EVIDENCING SYSTEM.